[REPAIR] Help in diagnosing my Old Panasonic Quintrix F TC-

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Sultanpepper123
Posts: 4
Joined: Mon May 16, 2022 7:34 am

[REPAIR] Help in diagnosing my Old Panasonic Quintrix F TC-

Post by Sultanpepper123 »

Hello everyone, I've had this for more than 20 years so it's quite sentimental. It was stored for a couple of years in storage and then we moved to another location and as you can see in the videos this was the surprise. I'm still trying to gather information and watch alot of videos to be as ready as
I can before opening the back as I am aware there are alot of hazardous areas back inside. BTW I've got the service manual.

The Problem :

TV is flickering and colours are not aligned (convergence issue ? ), not all input channels (composite/RCA) act the same and the Component Input acts differently I think. The video will speak a thousand words I'm sure.

Videos from each input channel

1- AV1 (Composite cable from a PS1 ):
https://www.youtube.com/watch?v=6lfxpImx8yE
2- AV2 (Composite cable from a PS1 ):
https://www.youtube.com/watch?v=LHWeE9C8_nE
3- AV3 (Composite cable from a PS1 ):
https://www.youtube.com/watch?v=x0LMW_M6MHc
4- DVD (Component cable from a OG Xbox ):
https://www.youtube.com/watch?v=FgS4MNPdFKM


TV Model : Panasonic Quintrix F TC-21P50R

I would really appreciate if any one would help me in sharing his/her thoughts on what are problems I'm having and where and how to fix them that would be really appreciated.

Background : I'm always looking to learn new things and in my free time I like to buy and fix broken stuff which is quite therapeutic.
Fatass
Posts: 32
Joined: Mon Sep 21, 2020 1:44 am

Re: [REPAIR] Help in diagnosing my Old Panasonic Quintrix F

Post by Fatass »

Hi, I'm not a technician but it looks like it's failing capacitors because of the strobing/flashes/lines onscreen. As to what part of the PCB(s) these caps are residing, I've no clue but it doesn't seem like the convergence is the main problem, which normally presents itself as spaced-apart red, green and blue lines in place of an otherwise white or uniformly colored line....then again, I'd need to be closer to the screen to see if that's also the case

I suspect it can also be caused by a bad diode in there, too.

I also have a Panasonic Quintrix F however I got it from a dude who was selling it off with low hours and is pretty large - 31" but I only use it for Dreamcast's VGA as it has d-sub input. Pity mine's a 100hz model, thus can't be used for lightgun games (except for, again, dreamcast lightgun games but honestly there are only a handful compared to the namco shooters on ps2.)

maybe find someone nearby who can fix it? I'm also in need of fixing a really sweet scart tv but most of the repairs near me no longer fix crts or only repair flatpanels.
War on hemorrhoids.
Sultanpepper123
Posts: 4
Joined: Mon May 16, 2022 7:34 am

Re: [REPAIR] Help in diagnosing my Old Panasonic Quintrix F

Post by Sultanpepper123 »

Fatass wrote:Hi, I'm not a technician but it looks like it's failing capacitors because of the strobing/flashes/lines onscreen. As to what part of the PCB(s) these caps are residing, I've no clue but it doesn't seem like the convergence is the main problem, which normally presents itself as spaced-apart red, green and blue lines in place of an otherwise white or uniformly colored line....then again, I'd need to be closer to the screen to see if that's also the case

I suspect it can also be caused by a bad diode in there, too.

I also have a Panasonic Quintrix F however I got it from a dude who was selling it off with low hours and is pretty large - 31" but I only use it for Dreamcast's VGA as it has d-sub input. Pity mine's a 100hz model, thus can't be used for lightgun games (except for, again, dreamcast lightgun games but honestly there are only a handful compared to the namco shooters on ps2.)

maybe find someone nearby who can fix it? I'm also in need of fixing a really sweet scart tv but most of the repairs near me no longer fix crts or only repair flatpanels.

Hello and thank you for taking the time for sharing your experience. I've opened up the TV and took out the Chassis ( Main PCB ) and measured voltage rails and they are very low. Secondary all are very low and the main offline regulator IC I've measured it's Vin Supply and it's supposed to be 16V but its 12-13V and it's fluctuating. Any ideas would be greatly appreciated as I'm nearing a dead end. :?

Note: I have the service manual and use the schematics as a guide , but I spend an entire day pulling out suspected components and measuring them ( caps and diodes ) but nothing was out of the ordinary....

BR
tongshadow
Posts: 613
Joined: Sat Jan 07, 2017 5:11 pm

Re: [REPAIR] Help in diagnosing my Old Panasonic Quintrix F

Post by tongshadow »

If you're getting different issues on different inputs, then I suspect something around the microprocessor is wrong. First, physically inspect the board and look for cracked solder joints or rings around through-hole components, specially capacitors.
Does the TV's OSD look fine without any inputs? Also, try connecting the Xbox Y (green) cable into the composite inputs and see what you get. The picture will be B/W of course.
Sultanpepper123
Posts: 4
Joined: Mon May 16, 2022 7:34 am

Re: [REPAIR] Help in diagnosing my Old Panasonic Quintrix F

Post by Sultanpepper123 »

tongshadow wrote:If you're getting different issues on different inputs, then I suspect something around the microprocessor is wrong. First, physically inspect the board and look for cracked solder joints or rings around through-hole components, specially capacitors.
Does the TV's OSD look fine without any inputs? Also, try connecting the Xbox Y (green) cable into the composite inputs and see what you get. The picture will be B/W of course.
Hi and thank you for the reply. The OSD looks very good. I've tried all the inputs Component, Composite and RF all give distorted images;

1. Composite : all in all bad screen humming sound as you can see in the youtube video , unfortunately I have no clue how to describe the fault .

2. Component : screen is ok but the colors are distorted and separated as in the video and I believe sound is not good as well.

3. RF input : screen is unviewable at all .

I've discovered that by hooking up the chassis board back to the crt the voltages readings were good; mainly voltages at the flyback IC were fine and at the secondary windings the voltage regulators outputs were fine as well.

I changed the vertical IC just for kicks but it did nothing .Also I tried recapping around the voltage regulators and the vertical IC .


BR
tongshadow
Posts: 613
Joined: Sat Jan 07, 2017 5:11 pm

Re: [REPAIR] Help in diagnosing my Old Panasonic Quintrix F

Post by tongshadow »

I believe we're looking at an issue in the video processing, nothing related to vertical deflection or voltage issues. I would investigate the components around the main IC (the one that processes video inputs into outputs) such as shorted diodes or open resistors.

Also, I downloaded the service manual for your TV and apparently it uses multiple boards, right?

Image

If so, check for cracked solder joints on the wire connectors and pins that connect the H-Board (Video processing board) to the A-Board (Main board). I think it's reasonable to assume the issue is between these boards, because the OSD is fine. The OSD is generated by the Jungle chip on the A-Board, and you also said you had audio issues, so it's safe to assume it could just be a poor contact cause by a dried solder joint, which is very common on these multi-boards.
Sultanpepper123
Posts: 4
Joined: Mon May 16, 2022 7:34 am

Re: [REPAIR] Help in diagnosing my Old Panasonic Quintrix F

Post by Sultanpepper123 »

tongshadow wrote:I believe we're looking at an issue in the video processing, nothing related to vertical deflection or voltage issues. I would investigate the components around the main IC (the one that processes video inputs into outputs) such as shorted diodes or open resistors.

Also, I downloaded the service manual for your TV and apparently it uses multiple boards, right?

Image

If so, check for cracked solder joints on the wire connectors and pins that connect the H-Board (Video processing board) to the A-Board (Main board). I think it's reasonable to assume the issue is between these boards, because the OSD is fine. The OSD is generated by the Jungle chip on the A-Board, and you also said you had audio issues, so it's safe to assume it could just be a poor contact cause by a dried solder joint, which is very common on these multi-boards.
Thank you for the reply, I forgot to mention I already reflowed the mating connectors solder jointsm but I will check continuity on the joints to their traces hopefully something comes up.

BR
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